1. Field of the Invention
The invention relates to a machine for producing a corrugated cardboard web lined at least on one side, comprising two fluted rollers for producing corrugations in a paper web, a glue application device for applying glue to tips of the corrugations of the corrugated paper web, and a pressing device for pressing a lined web against the tips provided with glue of the corrugated paper web which lies against one of the fluted rollers over a pressing region, wherein the pressing device has an endless pressing belt, which is guided over a deflection roller and a cylindrical tension roller and which is pressed against the fluted roller over the pressing region.
2. Background Art
In a machine of this type, which is known from EP 06 015 198.2 (corresponding to U.S. Ser. No. 11/459,744), the pressing device has a generally woven, screen-like pressing belt. If the tension roller is constructed in the conventional way so as to be cylindrical and intrinsically completely rigid, a slight stretch in the central region of the pressing belt occurs after only a relatively short operating time, and certainly before wear of the pressing belt usually occurs. This leads to a reduction in the contact pressure of the pressing belt on the central region of the corrugated cardboard to be produced. As a result, the adhesive bonds between the lined web and the corrugated paper web may be insufficient, which leads to corresponding defects in the quality of the corrugated cardboard web. The tension rollers have previously been configured so as to be crowned, meaning they decrease in diameter slightly from the centre of the roller to their axial outer ends. However this did not result in the desired improvement in quality.